Analysis Methods of Real-world Ammonia Emissions Using Small Type On-board Emissions Measurement System

Susumu Sato･Keigo Ashizawa･Chisato Fukunaga (Institute of Science Tokyo)･Noritsune Kawaharada (NALTEC)

In place of the PEMS used for RDE regulations, lightweight and compact on-board emission measurement devices that do not affect the vehicle weight are attracting attention. In this study, the dry-wet correction, delay time correction, and mass emission calculation necessary for analyzing NH3 emission were investigated based on the results of on-road measurements using a compact on-board emission measurement device installed in a gasoline vehicle.

Development of an LSTM Virtual Sensor for Vehicle Exhaust Ammonia Prediction

TIANYI GAO･KEIGO ASHIZAWA･SUSUMU SATO (Institute of Science Tokyo)

This study develops an LSTM-based virtual sensor for estimating vehicle exhaust ammonia (NH₃) emissions. Using on-board experimental data, the model learns temporal relationships among vehicle, engine and aftertreatment signals. Both direct and indirect prediction strategies are evaluated to compare their accuracy and robustness. Results show that the proposed approach effectively captures transient NH₃ behavior and provides a feasible method for real-time emission monitoring.

Effect of Precious Metal Species and Ceria-Zirconia Composition on Oxygen Storage Distribution in Three-Way Catalyst

Yuji Tokumasu･Yuki Watanabe (Institute of Science Tokyo)･Hiroyuki Itoyama･Chengwei Huang･Tsuyoshi Ishikawa (Nissan Motor)･Tsuyoshi Nagasawa (Institute of Science Tokyo)

To enhance the performance of three-way catalyst (TWC) and develop a numerical model, elucidating the oxygen release and storage mechanisms is key. In this study, oxygen isotope labeling experiments were conducted using a model catalyst consisting of dense oxygen storage material substrate coated with a precious metal. The effects of the TWC composition, such as the precious metal and the ceria-zirconia composition, on the oxygen storage distribution inside were visualized and analyzed.

Study on emissions calibration using catalyst physics model
-Calibration of target air-fuel ratio-

Tsuyoshi Ishikawa･Atsushi Morohoshi･Hiroyuki Itoyama･Yosuke Kubota (Nissan Motor)

Calibration of the target air-fuel ratio is important for emissions performance, and has been mainly conduct a actual engines until now. In this study, we developed an environment in which the control target value can be combined with the catalytic chemical reaction model, and developed a method to examine the matching value by the model. In this paper, the case of air-fuel ratio compatibility at engine starting is introduced together with the verification results using a high-speed gas analyzer.